Filter assembly for a vacuum cleaner

ABSTRACT

A filter assembly for a vacuum cleaner that includes a main housing having an inlet and an outlet. A motor moves air from the inlet to the outlet, and a first filter is arranged between the inlet and the outlet for filtering the air. An inner wall and an outer wall that is spaced apart from the inner wall form a cavity between the walls. The cavity is located between the first filter and the outlet. The inner wall has an inner opening that permits air to flow from the first filter into the cavity, and the outer wall has an outer opening. A back cover is removably secured to the outer wall over the outer opening to seal the cavity and guide the air from the cavity to the outlet. The back cover includes an access opening that is removably secured to the back cover over the access opening to seal the access opening. A filter cartridge is removably disposed within the cavity. The filter cartridge has a first side with a first opening and a second side opposite the first side and adjacent to the access cover with a second opening. The filter cartridge has a second filter, such as a HEPA filter, disposed therein between the first and the second openings for further filtering the air. A portion of the first side is in sealing engagement with a portion of the inner wall such that the first opening is aligned with the inner opening wherein the motor moves the air from the inner opening to the second opening.

RELATED APPLICATION

This application is a continuation application of assignee's pendingapplication Ser. No. 09/490,708, filed Jan. 25, 2000, now U.S. Pat. No.6,312,508; which is a continuation-in-part of assignee's pendingapplication Ser. No. 09/302,212 filed Apr. 29, 1999, now U.S. Pat. No.6,174,350, issued Jan. 16, 2001, which is a continuation-in-part ofapplication Ser. No. 09/298,137 entitled “Improved Filter for VacuumCleaner”, filed Apr. 23, 1999, now U.S. Pat. No. 6,162,287, issued Dec.19, 2000.

BACKGROUND OF THE INVENTION

This invention relates to a vacuum cleaner having primary and secondaryfilters, and more specifically, to an improved filter assembly for useas a secondary filter.

Vacuum cleaners operate by filtering dirty air that flows through a mainhousing between a vacuum cleaner inlet and outlet. One well-known typeof vacuum cleaner uses a primary filter that incorporates a basin filledwith liquid, preferably water. A separator driven by a motor separatesthe dirt particles from the air and deposits them into the water.Although such filter arrangements can be highly effective, inevitablythe vacuum cleaner filter is unable to filter all the air and smallerparticles of dirt escape through the outlet. To address this problem, asecondary filter has been incorporated to further filter the air. Thesecondary filter is arranged between the primary filter and the outletto trap very small dirt particles. A pleated fibrous filter, such as aHEPA filter, has been used that permits only virtually dirt-free air tobe expelled from the vacuum cleaner outlet.

It is difficult to provide the vacuum cleaner user convenient access tothe secondary filter located within the main housing when changing thefilter. Several components have been used as part of the filterassembly, and may be eliminated to reduce cost. The filter has not beenlocated within the housing in such a manner that ensures properplacement and easy replacement of the filter. Furthermore, when the userreplaces the filter one is confronted with a dirty filter that is messyand undesirable in appearance. Therefore, what is needed is aself-contained filter assembly having fewer components that isself-locating for easy replacement.

SUMMARY OF THE INVENTION AND ADVANTAGES

The present invention provides a filter assembly for a vacuum cleanerthat includes a main housing having an inlet and an outlet. A motormoves air from the inlet to the outlet, and a first filter is arrangedbetween the inlet and the outlet for filtering the air. An inner walland an outer wall that is spaced apart from the inner wall form a cavitybetween the walls. The cavity is located between the first filter andthe outlet. The inner wall has an inner opening that permits air to flowfrom the first filter into the cavity, and the outer wall has an outeropening. A back cover is removably secured to the outer wall over theouter opening to seal the cavity and guide the air from the cavity tothe outlet. The back cover includes an access opening that is removablysecured to the back cover over the access opening to seal the accessopening. A filter cartridge is removably disposed within the cavity. Thefilter cartridge has a first side with a first opening and a second sideopposite the first side and adjacent to the access cover with a secondopening. The filter cartridge has a second filter disposed thereinbetween the first and the second openings for further filtering the air.A portion of the first side is in sealing engagement with a portion ofthe inner wall such that the first opening is aligned with the inneropening wherein the motor moves the air from the inner opening to thesecond opening.

Accordingly, the above filter assembly provides a self-contained filterassembly having fewer components that is self-locating for easyreplacement.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention can be understood by referenceto the following detailed description when considered in connection withthe accompanying drawings wherein:

FIG. 1 is a partially broken perspective view of the vacuum cleaner ofthe present invention;

FIG. 2 is an exploded perspective view of the vacuum cleaner shown inFIG. 1;

FIG. 3 is a partial rear perspective view of the vacuum cleaner of FIG.1 with the back cover and filter cartridge of the present inventionremoved;

FIG. 4 is an exploded perspective view of the back cover and accesscover of the present invention;

FIG. 5 is a rear perspective view of the filter cartridge of the presentinvention; and

FIG. 6 is a front perspective view of the filter cartridge shown in FIG.5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A vacuum cleaner assembly is shown at 10 in FIGS. 1 and 2. Vacuumcleaners using a liquid basin or water pan filter are known to thoseskilled in the art as described in U.S. Pat. No. 5,096,475, which ishereby incorporated by reference to this specification. The vacuumcleaner assembly 10 includes a main housing 12 having an inlet 14 and anoutlet 16. The inlet 14 is preferably a round opening adapted to receivea vacuum hose. The outlet 16 includes a plurality of slotted vents 19opposite the inlet 14. A motor 17 is supported within the main housing12 between the inlet 14 and the outlet 16 for drawing air into the inlet14 and exhausting air outwardly through the outlet 16. A primary orfirst filter, such as a water pan 20 filled with a liquid filter mediumsuch as water, is arranged below the motor 17 between the inlet 14 andoutlet 16. A separator 22 is driven by the motor 17 for separating dirtparticles in the air and depositing them into the water in the water pan20.

Referring to FIGS. 2 and 3, the main housing 12 has an inner wall 30 andan outer wall 32 spaced apart from the inner wall 30 forming a cavity 34between the walls 30, 32. The main housing 12 may utilized severalcomponents to form the inner 30 and outer 32 walls. The cavity 34 isinterposed between the water pan 20 and the outlet 16. The inner wall 30has an inner opening 40 toward the interior of the main housing 12 thatpermits air to flow from the water pan 20 into the cavity 34. As shownin FIG. 3, air flows through the inner opening 40 and between the walls30, 32, finally exiting through the outlet 16. The outer wall 32, orexterior wall of the main housing 12, has an outer opening 42 thatprovides access to the cavity 34. A back cover 44 is removably securedto the outer wall 32 over the outer opening 32 to seal the cavity 34 andguide or direct the air from the cavity 34 to the outlet 16.

Referring to FIG. 4, the back cover 44 has an access opening 46 that issealed by an access cover 48 removably secured to the back cover 44 overthe access opening 46. The back cover 44 may be secured using threadedfastener, or tabs 50 integrally formed with the back cover 44 that coactwith the outer wall 32. The access cover 48 is preferably secured to theback cover 44 by tabs 52. The access cover 48 is removed for use of ablower attachment, which is discussed in more detail below. The backcover 44 includes a cleat assembly 54 integral with the back cover 44for stowing an electrical cord. The cleat assembly 54 is of the typedisclosed in U.S. Pat. No. 5,924,642, which has retractable retainingarms 56 movable between retracted and extended positions. Byincorporating the electrical cord cleat assembly 54 into the back cover44, several components may be eliminated thereby simplifying assemblyand reducing cost.

The filter cartridge 60 of the present invention is removably disposedwithin the cavity 34. With reference to FIGS. 5 and 6, the filtercartridge 60 has a first side 62 with a first opening 64 and a secondside 66 opposite the first side 62 with a second opening 70. The secondside 66 is adjacent to the back cover 44 with the second opening 70aligned with access cover 48. The filter cartridge 60 comprises first 76and second 78 portions, respectively including first 62 and second 66sides, are secured to one another, preferably by welding. A secondfilter 80, preferably a HEPA filter, is disposed between the portions76, 78. Air flows through the filter 80 from the first opening 64 to thesecond opening 70. When the second filter 80 needs replacement, thewhole filter cartridge 60 is replaced. In this manner, the messy filter80 is retained within the clean filter cartridge 60 so that the userdoes not get dirty changing the filter 80. Additionally, a cleaner, morepleasing appearance is provided to the user.

A foam seal 82 is secured to a portion of the first side 62 around thefirst opening 64. The filter cartridge 60 is installed into the cavity34 in sealing engagement with a portion of the inner wall 30 with thefirst opening 64 being aligned with the inner opening 40. The foam seal82 ensures that the air flows through the second filter 80 and does notleak past the filter cartridge 60. The first portion 76 may includelouvers 84 that extend across the first opening 64 for directing the airacross the second filter 80 in a desired path.

To locate the filter cartridge 60 within the cavity 34, the outer wall32 includes an aperture 88, preferably at the bottom of the outeropening 42. The filter cartridge 60 includes a downwardly depending tab90 adapted to be received in the aperture 88 (shown in FIG. 3) forlocating the filter cartridge 60 within the cavity 34. When the backcover 44 is removed, the filter cartridge 60 may be tilted forward forremoval from the cavity 34. The second portion 78 includes at least oneoutwardly extending leg 92 for coacting with the back cover 44 andlocating the filter cartridge 60 at a distance from the back cover 44 topermit the air to flow from the second opening 70 to the outlet 16uninhibited.

The second portion 78 includes a collar 96 about the second opening 70for a blower attachment when the access cover 48 is removed. The blowerattachment may then be installed into the collar 96.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology that has been used is intended to bein the nature of words of description rather than of limitation.Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:
 1. A filter assembly for a vacuum cleanercomprising: a housing having an inlet and an outlet; a first filter forfiltering air prior to being exhausted outwardly through said outlet; afilter cartridge disposed in a cavity formed by the housing between thefirst filter and the outlet; a back cover removably secured to housingover an outer opening to seal the cavity, the back cover having anaccess opening; an access cover removably secured to the back cover oversaid access opening to seal said access opening.
 2. A filter assembly,as set forth in claim 1, wherein the filter cartridge has a first sidewith a first opening and a second side opposite the first side andadjacent to the access cover with a second opening, the filter cartridgehaving a second filter disposed therein between the first and the secondopenings for further filtering the air, and a portion of the first sidein sealing engagement with a portion of the housing with the firstopening being aligned with an inner opening of the housing.
 3. A filterassembly, as set forth in claim 2, including a motor for moving air fromthe inlet to the outlet.
 4. A filter assembly, as set forth in claim 3,including a separator driven by the motor, and wherein the first filtercomprises a basin filled with liquid for filtering the air.
 5. A filterassembly, as set forth in claim 2, wherein the housing includes an innerwall and an outer wall spaced apart from the inner wall, the cavitybeing formed between the walls, the cavity interposed between the firstfilter and the outlet, the inner wall having an inner opening permittingair to flow from the first filter into the cavity and the outer wallhaving an outer opening.
 6. A filter assembly, as set forth in claim 5,wherein the inner and the outer walls are formed by the housing.
 7. Afilter assembly, as set forth in claim 6, wherein the filter cartridgeincludes first and second portions secured to one another and furtherincludes a second filter disposed therebetween.
 8. A filter assembly, asset forth in claim 7, wherein the first and said second portions aresecured to one another by welding.
 9. A filter assembly, as set forth inclaim 8, wherein the first portion includes a foam seal attached theretoabout the inner opening for sealing against the inner wall.
 10. A filterassembly, as set forth in claim 8, wherein the first portion includeslouvers extending across the inner opening for directing the air acrossthe second filter in a desired path.
 11. A filter assembly, as set forthin claim 2, wherein the housing includes an aperture and the filtercartridge includes a depending tab adapted to be received in theaperture.
 12. A filter assembly, as set forth in claim 2, wherein thehousing includes at least one outwardly extending leg for coacting withthe back cover and locating the filter cartridge at a distancetherefrom.
 13. A filter assembly, as set forth in claim 2, wherein thefilter cartridge includes a HEPA filter.
 14. A filter assembly, as setforth in claim 2, wherein the access cover includes a plurality ofattachment tabs adapted to coact with the back cover for removablysecuring the access cover thereto.
 15. A filter assembly, as set forthin claim 2, wherein the back cover includes a cleat assembly integralwith the back cover for stowing an electrical cord, said cleat havingretractable retaining arms movable between retracted and extendedpositions.
 16. A filter assembly for a vacuum cleaner comprising: ahousing having an inlet and an outlet and defining a cavity; a firstfilter interposed between said inlet and said outlet for filtering theair; a back cover removably secured to said outer wall over said outeropening, said back cover having an access opening; an access coverremovably secured to said back cover over said access opening; and afilter cartridge removably disposed within the cavity, said filtercartridge having a first side with a first opening and a second sideadjacent to said access cover with a second opening, said filtercartridge having a second filter disposed between said first and secondsides, and a portion of the first side in sealing engagement with aportion of the housing.